Fume neutralizer



Jan. 7, 1941. E 1 FRANWlQkl 2,228,135

FUME NEUTRALIZER Filed l July 10h, 1939 Patented Jan. 7, 1941 UNITED STATES -rATizruv OFFICE Application July 10, 1939, Serial N0. 283,629

8 Claims.

My invention relates to a fume neutralizer, such as employed for cleaning or pickling of dentures, jewelry, and various articles of gold or other precious metals.

In the process of pickling or cleaning articles of the type mentioned, a bath of hydrochloric acid or some other suitable cleaning or pickling agency is provided in which the articles to be treated are placed and the fumes from this bath, generated by heating of the latter, is caused to be passed through a saturated solution of bicarbonate of soda or similar neutralizing substance and be thus neutralized preparatory to escaping from the device.

One of the objects of my invention is to provide a neutralizer of the kind mentioned which is simple in construction, inexpensive to manufacture, and capable of being constructed of refractory or other suitable acid-resisting material. Another object of my invention is to provide a neutralizer of the kind mentioned, comprising several separable parts which are assembled and connected to form a unitary structure and so constructed that a suitable heater can be quickly and conveniently associated therewith so that it may be placed in operative position to quickly heat the contents of the acid receptacle or be removed therefrom in order that the acid receptacle will |cool quickly and thus result in a more efficient method of operation than has heretofore been possible.

A still further object is to provide a suitable support or base and suspend therein an acid pot or receptacle on which is mounted a soda pot or receptacle provided with an axial open-ended tube or tower and which soda pot or receptacle has depending thereinto a control bell or trap fastened to the soda pot or receptacle with the latter `fastened to the aci-d pot or receptacle by means of a suitable clamping device 'so as to form a substantially unitary structure easily conveyed from one place to another.

With the above and other objects to appear l hereinafter, my invention consists in the novel features of construction and in the arrangement and combination of parts to be hereinafter -described and more particularly pointed out in the subjoined claims. l

In the drawing,

Fig. 1 is a vertical section through a device constructed in accordance with my invention.

Fig. 2 is a cross section taken on line 2-2, Fig. 1.

Fig. 3 is a cross section taken on line 3 3, Fig. 1.

Fig. 4 is a detached perspective View of the support or base of the device on a reduced scale.

Fig. 5 is a detached perspective View of the control bell or trap on a reduced scale.

Fig. 6 'is an enlarged'vertical section taken on line 66, Fig. 1.

The support or ba'se 1, preferably formed of refractory material, is in the form of an inverted cup, the peripheral wall or which is preferably ilared downwardly and provided at diametrically opposite regions with large openings 8 which extend upwardly from the bottom of the base. The upper end of this support or base is provided with alarge central opening 9, forming thereby an inwardly-extending supporting flange I0 at the upper end of said peripheral wall.

Bearing against the said ange l0 is a washer ll, and resting upon said washer is a iiange or rim l2 extending outwardly from an acid pot or receptacle I3; the latter being passed through the opening 9 in said base and receiving support from the flange Il) of the latter. The flange l2 of the acid pot or receptacle is provided at diametrically opposite points with bosses I4 for a purpose to appear hereinafter.

The acid pot or receptacle is provided with a counterbore l'5 at its upper end to form an upwardly-extending shoulder L6 against which a rubber `or similar gasket il is seated. Thus the interior of said acid receptacle may be said to be enlarged at its upper end to receive the lower end of what I term a soda pot or receptacle I8. This soda pot or receptacle is open at its upper end and has its lower end resting on the gasket Il. The bottom wall of this soda pot or receptacle is inclined upwardly toward the axis of the same, as at` I9, and rising axially from said bottom is an upwardly tapering vapor tube or tower 2li which extends upwardly to or within a short distance of the upper edge of the soda pot or receptacle, said tube being open at opposite ends.

2| designates what I term a control bell or trap which may be referred toas an inverted cup having an outstanding flange 22 at its upper end resting upon the upper edge of the soda pot or receptacle I8. I, however, prefer to describe this bell or trap as having a |cover 23 from which depends a circular wall 24 spaced from the peripheral wall 25 of the soda pot or receptacle and more distantly from the axial tube or tower 20 of the latter. The depending circular wall 24 of this control bell terminates within the soda pot or receptacle a short ydistance from the bottom of the latter, and at its lower end comparatively small notches or openings l26 are formed which may be spaced equidistantly around said wall. A substantially U-shaped `cushioning ring 21 is fitted over the upper edgeof the soda pot or receptacle and against this cushioning ring rests the marginal portion of the cover 23, or in other words, the flange portion 22. Since the two parts of the device between which said cushioning ring is disposed are constructed of refractory material,

chipping or other damage to said parts is prevented.

Connecting the annular space 28 between the peripheral Wall of the soda pot or receptacle and the depending circular wall 24 of the lbell or trap with the outer or atmospheric air are a number of escape openings 29.

The washer mounted on the support or base and on which the ange or rim I2 of the acid pot rests, serves as a cushion, rather thana packing, so as to guard against both the inwardly extending anges I of the fba'se and the flange or rim |2 of the acid pot becoming broken or fractured, due to the fact that these parts are formed of refractory material. The gasket I1, however, interposed between the upper end of the acid pot and the lower end of the soda pot, is to be ycompressed so as to serve as .a seal or packing and prevent the escape of acid fumes around this region. To assure proper packing or sealing at such region, a clamp device 30 is employed 4which comprises a yoke member 3| positioned across the cover 23 and has clamp arms 32 at opposite ends which extend downwardly and have their lower terminals bent inwardly, as at 33, for entrance into sockets or recesses 34 opening outwardly in the bosses I4 formed on the flange or rim I2 of the acid pot.

The yoke member 3| is provided centrally between its ends with a screw-threaded opening 35 into which a pressure-screw 36 is threaded; said `screw having a knurled head 31 or being otherwise provided with means for conveniently rotating the same. The outer surface of the cover 23 is provided with an axial depression 38 in which is located a swveled pressure-member or disk 39 recessed at the bottom to form an annular wall 40, the lower edge of which rests against the bottom of said depression 38. Through the top wall of this pressure-member or disk a reduced portion 4| of said pressurescrew is passed; this pressure-member or disk being fastened in place on the lower end of the pressure-screw by upsetting a further reduced portion 42 of the pressure-screw, as at 43, the further reduced portion of said pressure-screw 36 being passed through a washer 44 which bears against the under side of the top wall of said. pressure-member or disk. The said washer and the upset lower end of the pressure-screw is confined within the recessed portion of the pressuremember so that the latter only cornes in contact with the refractory material from which the control bell is formed. By rotating the pressurescrew 36, after having properly positioned the clamp device, the control bell or trap is rmly clamped to the soda pot and the latter to the acid pot so that leakage of fumes from the latter cannot take place.

The combined weight of the acid pot or receptacle I 3, the soda pot or receptacle I8, the control bell or trap 2|, and the clamp device 30 is carried by the base 'I and cushioned on the latter by the cushioning washer Within the acid pot I have shown a bath of hydrochloric acid which may, however, be any other suitable pickling or cleansing solution, and which is designated by the numeral 45; and 46 designates a saturated solution of bicarbonate of soda or some similar substance possessing the ability to neutralize the acid fumes rising from the acid pot in the manner to be hereinafter described.

It is to be noted that the control bell or trap 2|.-has its lower portion entered in the neutralizing solution 45, and normally the portion of this solution within the control bell or trap is on the level with that portion surrounding it.

41 designates a suitable heater; that illustrated being an electrical heater which is positioned directly underneath the acid pot I3, the heating element 48 of which is either in contact with the bottom of the acid pot 0r in close proximity thereto.

This heater may be of any approved construction, or other means may be resorted to for heating the acid within the acid pot. A heater of the type shown or one easily introduced from one or the other side of the base 1 through one of the openings 8 formed therein is preferably employed because of the advantage derived from the use of a removable heater when taken in conjunction with the type of base employed, as will be presently described.

The level of the neutralizing solution under normal conditions is indicated by the line 49 and under such conditions no pressure is created within the acid pot or the soda pot, nor within the bell or trap fitted into the soda pot. Upon the application of heat by means of the heater 41, the acid within the acid pot becomes heated and the neutralizing solution 46 Within the soda pot remains at its normal level indicated at 49,*until pressure within the acid pot is created and the vapors therefrom enter the control bell or trap 2| through the medium of the axial tube or tower 20 rising from the bottom of the soda pot. It is of course understood that dentures, bridge work, articles of jewelry or other objects to be cleaned or treated are placed within the acid bath 45 and, as the latter is heated, the vapors therefrom rise under pressure through the tube or tower 20, and upon entering the control bell lowers the neutralizing solution within the latter to approximately the dotted line which in turn causes the level of the neutralizing solution surrounding the control bell or trap to rise to approximately the point indicated by the dotted line 5|. At such times air within the device diluted with hydrogen chloride, or in other words with hydrogen chloride gas, escapes from the control bell or trap through the small notches 2B formed in the lower end of the latter and rises in the form of bubbles through the volume of the neutralizing solution surrounding said control bell or trap. During this travel `of the hydrogen chloride gas, the air will be gradually expelled before the gas, but the gas will be completely neutralized in its upward passage through the solution of bicarbonate of soda or other neutralizing agent employed so that the vapors and air may escape through the escape openings 29 without carrying with it any of the objectionable fumes, which would otherwise be obnoxious and injurious to individuals employed, and damaging to surrounding articles. Itis of course understood that these bubbles are created because of the pressure exerted against the depressed portion of the neutralizing solution partly sealing the lower end of the control bell or trap. This neutralizing solution may, therefore, be said to also serve as a liquid seal to prevent the escape of gases until a predetermined pressure is established in both the acid pot I3 and the upper end of the bell or trap 2|, after which the gases, properly neutralized, may escape from the device.

I desire at this point to state that while the small notches 26 in the lower edge of the control bell or trap are highly desirable, they may be dispensed with; but in the event that the device is not set upon a level surface, the hydrogen chloride gas might escape as large globules'around only a` portion of the lower edge of the control bell or trap. The `notches 26, even though the 5 devicewere not set on a level surface, prevent the escape of the gas in such manner. Experiments have shown, however, that with the pressure'built up to approximately one and one-half ounces per square inch, the device will function efficiently even though the notches 26 are dispensed with, although not as perfectly as when such notches are used.

From the foregoing it will be apparent that the control bell or trap acts as a seal between the neutralizing pot or chamber and the atmosphere.

rIhis device is particularly adapted for dental work; for example, in the removal of porcelain teeth from dental bridge work, wherein the teeth Iare cemented in place, the hydrochloric acid or other pickling or cleansing solution in the acid pot is heated to a temperature to create the pressure above mentioned and therefore acts very quickly on the cement so as to loosen the teeth therefrom.

The methods heretofore employed in dental work embodied the heating or boiling of the acid in a' manner that would cause the objectionable fumes therefrom to rise and escape into the room,

land Vfans `or suction devices were employed to carry away these fumes because of their effect on the health of the individuals and the damage created to metallic objects within the vicinity of the acid bath. With this device it is possible to bring the acid quickly to a higher temperature than has heretofore been possible, Without the danger of the fumes causing deteriorating effect upon surrounding objects or injury to people.

I particularly wish to stress the fact that the small notches 26 in the lower edge of the control bell er trap enable the gases to escape through small segregated areas in small segregated gas streams, so that these gas streams become broken in their ascent through the portion of the neutralizing solution surrounding the control bell or trap and escape as small ybubbles in neutralized form because of the chemical change taking place during such action.

After the necessary period of pickling or cleansing of dental work, or jewelry, or after removing teeth from bridge work Iand the like, the heating device 4l is withdrawn from the support or base 1, preferably after turning off the current employed for heating the acid. The

` two large openings 8 formed in the base then provide for a free circulation of the cooler surrounding air and thus aid in quickly lowering the temperature of the acid within the acid bath, thereby creating a vacuum Within the acid pot and-the control chamber, which latter may be said to comprise the soda pot and the bell or` trap, so as to cause air to -be drawn through the escape openings 29 in the cover 23. This air acts to depress the volume of the neutralizing solution surrounding the control bell or trap and cause it or at least portions thereof to pass around the lower edge of said bell or trap and rise within the latter until the level of the acid outside of the control bell reaches the line indicated by small ms and designated by the numeral 52 and until the solution Within the control bell or trap rises to approximately the line 53 indicated by the small s within said bell or trap. The action of the Iair is therefore reversed from that of the acid vapors, and` air bubbles are caused to travel upwardly within the control bell or trap from the small notch-es 2S in the lower edge thereof, entering said bell or trap above the level of the solution therein and passing down through the tube or tower 2D into the acid pot. rFhere being 5 no pressure in the device, it may then be opened without any escape of dangerous acid fumes or Without the hydrochloric acid puffing out from the acid pot.

With this in view it is only necessary to loosen l0 the pressure screw 35 so as to enable the connected clamp arms 32 to swing on their inwardly bent extremities 33, after which the clamp device can be completely removed and the soda pot with its control bell lifted from the acid pot to gain 15 easy access to the latter.

From the foregoing it will be apparent that I have devised a simple and inexpensive fume neutralizer, by means of which the acid within the acid pot can be brought to a higher tempera- 20 ture than heretofore in the act of treating dentures, bridge work, or other articles, without danger of the fumes rising therefrom contaminating surrounding objects or injuring people engaged in the vicinity of the device. The acid 25 within the acid pot may be at any desired level, and the solution in the neutralizing pot is brought to a level determined by a line marked on the side-of this pot, which may `be referred to as the soda water level; and as long as the level is 30 maintained in this pot the -solution therein will not, at any time, rise to the escape perforations 29 and pass through the same while under the pressure created by the boiling of the acid within the acid pot; nor will said solution, `while underl 35 vacuum, due to the cooling of the acid pot, risev to the upper end of the vapor tube or tower 2o. This is accomplished by proportioning the diameters of the soda pot and the control bell substantially as illustrated. 40

Having thus described my invention, what I claim is:

1. A fume neutralizer for cleaning, piclrling and otherwise treating articles, comprising a base of inverted cup-shape formation having compara- 45 I tively large air circulating openings at diametrically opposite regions and provided at its upper end with an inwardly-extending supporting ange forming a large axial opening in the top of saidY base, an acid pot of cup formation pro- 50 vided with an outstanding rim at its upper end receiving support from said flange and projected through said large axial opening into said base, a neutralizing pot supported by said acid pot,'a gasket between said lacid pot and said neutraliz-` 55 ing pot, a heating device in said base insertibley thereinto and removable therefrom through one of said circulating openings, and means exerting pressure downwardly upon said neutralizing pot for compressing said gasket and rendering the 60 acid pot vapor-tight -around the region of supportthereon by said neutralizing pot.

2. A fume neutralizer for cleaning, pickling and otherwise treating articles, comprising a base having an opening at its upper end, an acid pot 65 supported by said base and projecting through said opening, a neutralizing pot resting upon the upper end of said acid pot and sealed to prevent the escape of acid fumes from the latter, said neutralizing pot containing a fume-neutralizing 70 solution and being open at its upper end, said neutralizing pot having an upwardly-extending tube serving as a means of communication between said acid pot and said` neutralizing pot,

and a ,cover vfor saidy neutralizing pot having` a 7,5.`

depending wall extending into the fume-neutralizing solution within said neutralizing pot, said cover being provided with openings serving as means of communication between the interior of said neutralizing pot and the atmosphere.

3. A fume neutralizer for cleaning, pickling and otherwise treating articles, comprising an acid pot containing a suitable acid, means to support said acid pot in elevated position, a heating device beneath said acid pot, a neutralizing pot superimposed on said acid pot and containing a fume-neutralizing solution, said neutralizing pot having an axial tube extending upwardly from its bottom serving as a means of communication between the interiors of said acid pot and said neutralizing pot and having also a cover provided with escape openings and a depending wall positioned between the peripheral wall of said neutralizing pot and said axial tube and terminating short of the bottom of said neutralizing pot, thereby forming a seal between the upper end of said axial tube and said escape openings, and means to fasten said neutralizing pot to said acid pot.

4. A fume neutralizer for cleaning, pickling and otherwise treating articles, comprising an upwardly-opening acid pot provided with an outstanding rim at its upper end and being internally enlarged at its upper end to form an upwardlyfacing shoulder, a gasket bearing against said shoulder, a second pot containing an acid neutralizing agent surmounting said acid pot and resting upon said gasket, said second pot having a tube rising from its bottom serving as a means of communication between the interiors of said acid pot and said second pot, and a cover for said second pot having a depending wail surrounding said axial tube and spaced from the peripheral wall of said second pot, said depending wall terminating in spaced relation to the bottom of said second pot, said cover having openings formed therethrough to serve as a means of communication between the space separating said depending wall from said peripheral wall and the atmospheric air, and a clamp device serving to exert pressure against said cover and said second pot to effectively seal the latter from said acid pot.

5. A fume neutralizer comprising a base of inverted cup formation having an opening in its upper end, an acid pot extending through said opening and having a rim resting upon the upper end of said base around said opening, said base and acid pot being formed of refractory material, means to cushion said rim from said base, a second pot containing a neutralizing solution resting upon the upper end of said acid pot and sealed therefrom, a cover for said second pot, and means in the construction of said second pot and cover to form a seal within said second pot utilizing said neutralizing solution as a liquid seal, said cover having openings leading to the atmospheric air and said liquid seal causing the acid lf umes to be trapped within said second pot and .passed `through said liquid seal toi escape through the openings in said cover in the form of carbon dioxide, and a clamp Ydevice for maintaining the seal between said acid pot and said secondpot.

6. A fume neutralizer comprising a base adapted to rest upon a foundation, an acid pot open at `its upper lend receiving support from said base and having its bottom spaced from said foundation, a heating device positioned within said base underneath'saidacid pot, a second pot containing a neutralizing solution closing the upper end of said acid pot and containing a fume-neutralizing solution, a sealing gasket between said two pots, said second pot having an upwardly-extending tube serving as a means of communication between the interiors of said pots and having its upper end terminating above the normal level of said fume-neutralizing solution, the top of said second pot having a depending wall surrounding said upwardly-extending tube and in spaced relation thereto and being also in spaced relation to the peripheral wall of said second pot, said depending wall having its lower portion submerged in said fume-neutralizing solution, the top of said second pot having openings therein placing the interior of said second pot in communication with the atmospheric air, and means to maintain the seal between said two pots.

'7. In a fume neutralizer, a neutralizing chamber containing a neutralizing solution and adapted to receive acid fumes, said chamber having a top wall and a bottom and having escape openings in said top wall for the escape of the neutralized fumes, a wall depending from said top wall endless in cross section and having its lower end terminating within said neutralizing solution, means for delivering the acid fumes to the area surrounded by said depending wall above the neutralizing solution within said chamber, said depending wall being provided at its lower end with comparatively small notches through which the acid fumes pass and which fumes rise through said solution into the space between said depending wall and the peripheral wall of said chamber, the openings in said cover serving as a means of communication between said lastrnentioned space and the atmospheric air.

8. A fume neutralizer for cleaning, pickling or otherwise treating other small articles, comprising a base of refractory material and of inverted cup-shape formation having a large opening at its upper end and large openings in its peripheral wall at diametrically opposite regions, a cushioning element resting on the area of said base around said first-mentioned opening, an acid pot formed of refractory material and having a rim at its upper end resting upon said cushioning element and internally enlarged in diameter within said rim to form an upwardly-facing shoulder',

said rim being provided with sockets at diametrically opposite points and resting upon said cushioning element, a gasket on said upwardly-facing shoulder, a neutralizing pot resting upon said gasket, said neutralizing pot comprising a body portion and a cover, said body portion having an axial tube extending upwardly from its bottom and said cover having an annular depending wall in spaced relation to said axial tube and the peripheral Wall of said body portion and terminating within said neutralizing solution, a cushioning element between the marginal portion of said cover and the upper end of said body portion, said cover having openings serving as means of communication between the space surrounding said annular depending wall and the atmospheric air, a clamp device comprising a yoke member extending across the top of said cover, clamp arms depending from opposite ends of said yoke member and having inwardly .bent terminals entered in the sockets formed in the rim of said acid pot, and a screw passed through said yoke member centrally between its ends and exerting pressure against said cover.

EDMOND J. FRANWICK. 

